Walcott says the win at Bayern Munich shows they have players unafraid to step up.
"We had a lot of leaders out there telling people what to do, there was a bit more communication than there has been previously," he told arsenal.com.
"We care, we wanted to prove to everyone that we want to win and the desire and commitment was there.
"We have definitely been too quiet in the past, we have been afraid to tell each other what to do at times but we did that [against Bayern]. It is not about having a go at each other, it is speaking out when it is needed."